插入操作

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Overview
插入单一文档
插入多个文档
Insert Example: Full File
更多信息

Overview

在本指南中，您可以了解如何使用 MongoDB Java 驱动程序插入文档。

您可以使用MongoDB来检索、更新和删除信息。要执行任何这些操作，用户配置文件和订单等信息需要存在于MongoDB中。要使该信息存在，请首先执行插入操作。

插入操作使用insertOne() 、 insertMany()和bulkWrite()方法将单个或多个文档插入MongoDB 。

以下部分重点介绍insertOne()和insertMany() 。有关如何使用bulkWrite()方法的信息，请参阅我们的批量操作指南。

注意

The id_ Field in Insert Operations

When inserting a document, MongoDB enforces one constraint on your documents by default: each document must contain a unique _id value. Duplicate _id values violate unique index constraints, resulting in a WriteError.

管理该字段有两种方法：

您可以自己管理该字段，确保使用的每个值都是唯一的。
您可以让驱动程序自动生成唯一的 ObjectId 值。

除非您为唯一性提供了强有力的保证，否则我们建议让驱动程序自动生成 _id 值。

For more information about unique indexes, see the manual entry on Unique Indexes.

插入单一文档

如果要插入单个文档，请使用 insertOne() 方法。

成功插入后，该方法将返回一个InsertOneResult 实例，该实例表示新文档的_id。

例子

以下示例使用insertOne()方法创建并插入文档：

Document doc1 = new Document("color", "red").append("qty", 5);
InsertOneResult result = collection.insertOne(doc1);
System.out.println("Inserted a document with the following id: " 
    + result.getInsertedId().asObjectId().getValue());

上述代码的输出如下所示：

Inserted a document with the following id: 60930c39a982931c20ef6cd6

有关部分提及的方法和类的更多信息，请参阅以下资源：

insertOne() API 文档
InsertOneResult API 文档
insertOne()手册解释
Runnable 插入文档示例

插入多个文档

如果要插入多份文档，请使用 insertMany() 方法。此方法将按指定的顺序插入文档，直到发生异常（如果有）。

例如，假设您要插入以下文档：

{ "_id": 3, "color": "red", "qty": 5 }
{ "_id": 4, "color": "purple", "qty": 10 }
{ "_id": 3, "color": "yellow", "qty": 3 }
{ "_id": 6, "color": "blue", "qty": 8 }

如果您尝试插入这些文档，则在插入第三个文档时会发生WriteError ，并且发生错误之前的文档仍会插入到您的集合中。

提示

在错误发生之前，使用 try-catch 区块获取已成功处理文档的确认：

List<Integer> insertedIds = new ArrayList<>();
// Inserts sample documents and prints their "_id" values
try {
    InsertManyResult result = collection.insertMany(documents);  
    result.getInsertedIds().values()
        .forEach(doc -> insertedIds.add(doc.asInt32().getValue()));
    System.out.println("Inserted documents with the following ids: " + insertedIds);
// Prints a message if any exceptions occur during the operation and the "_id" values of inserted documents
} catch(MongoBulkWriteException exception) {
    exception.getWriteResult().getInserts()
        .forEach(doc -> insertedIds.add(doc.getId().asInt32().getValue()));
    System.out.println("A MongoBulkWriteException occurred, but there are " + 
        "successfully processed documents with the following ids: " + insertedIds);
}

输出由 MongoDB 可以处理的文档组成，应如下所示：

A MongoBulkWriteException occurred, but there are successfully processed
documents with the following ids: [3, 4, 6]

如果您查看集合内部，应该会看到以下文档：

{ "_id": 3, "color": "red", "qty": 5 }
{ "_id": 4, "color": "purple", "qty": 10 }

成功插入后，该方法会返回一个InsertManyResult实例，表示每个新文档的_id 。

例子

以下示例创建两个文档并将其添加到List中，并使用insertMany()方法插入List ：

List<Document> documents = new ArrayList<>();
Document doc1 = new Document("color", "red").append("qty", 5);
Document doc2 = new Document("color", "purple").append("qty", 10);
documents.add(doc1);
documents.add(doc2);
InsertManyResult result = collection.insertMany(documents);
// Retrieves and prints the ID values of each inserted document
List<ObjectId> insertedIds = new ArrayList<>();
result.getInsertedIds().values()
    .forEach(doc -> insertedIds.add(doc.asObjectId().getValue()));
System.out.println("Inserted documents with the following ids: " + insertedIds);

上述代码的输出如下所示：

Inserted documents with the following ids: [60930c3aa982931c20ef6cd7,
60930c3aa982931c20ef6cd8]

Insert Example: Full File

注意

Example Setup

This example connects to an instance of MongoDB by using a connection URI. To learn more about connecting to your MongoDB instance, see the 创建 MongoClient guide. This example also uses the movies collection in the sample_mflix database included in the Atlas sample datasets. You can load them into your database on the free tier of MongoDB Atlas by following the Get Started with Atlas Guide.

The following code is a complete, standalone file that performs an insert one operation and an insert many operation:

// Inserts a sample document describing a movie by using the Java driver
package org.example;
import java.util.Arrays;
import org.bson.Document;
import org.bson.types.ObjectId;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.result.InsertOneResult;
import com.mongodb.client.result.InsertManyResult;
import java.util.List;
public class Insert {
    public static void main(String[] args) {
        // Replace the uri string with your MongoDB deployment's connection string
        String uri = "<connection string uri>";
        try (MongoClient mongoClient = MongoClients.create(uri)) {
            MongoDatabase database = mongoClient.getDatabase("sample_mflix");
            MongoCollection<Document> collection = database.getCollection("movies");
            // Inserts a sample document describing a movie into the collection
            InsertOneResult result = collection.insertOne(new Document()
                    .append("_id", new ObjectId())
                    .append("title", "Ski Bloopers")
                    .append("genres", Arrays.asList("Documentary", "Comedy")));
            // Prints the ID of the inserted document
            System.out.println("Inserted document id - insert one: " + result.getInsertedId());
            // Creates two sample documents containing a "title" field
            List<Document> movieList = Arrays.asList(
                    new Document().append("title", "Short Circuit 3"),
                    new Document().append("title", "The Lego Frozen Movie"));
            // Inserts sample documents describing movies into the collection
            InsertManyResult result = collection.insertMany(movieList);
            // Prints the IDs of the inserted documents
            System.out.println("Inserted document id - insert many: " + result.getInsertedIds());
        }
    }
}

insertOne() document id: BsonObjectId{value=...}
insertMany() document ids: {0=BsonObjectId{value=...}, 1=BsonObjectId{value=...}}